We have a Support Tool that will gather relevant information for us to debug the issue. Could you please download and execute it on the machine where the stack is running by following the steps described in the guide below?

Thank you for the reply. I am using a Bitnami VM appliance (bitnami-moodle-3.1.2-0-linux-ubuntu-14.04-x86_64), I am trying to upgrade from Moodle 3.1+ (Build: 20160616), PHP version 5.5.27. I have https enabled as well as removal of the bitnami landing page. The support tool generates files in a zip: